international journal of current research in multidisciplinary … · 2020. 1. 6. · average 84.7...

International Journal of Current Research in Multidisciplinary (IJCRM) ISSN: 2456-0979 Vol. 4, No. 9, (November’19), pp. 10-18

Copyright ⓒ 2016 IJCRM | 0 |

FLASH FLOODS IN HIMALAYA WITH SPECIAL

REFERENCE TO MORI TEHSIL OF UTTARAKHAND, INDIA

SUSHIL KHANDURI1, K. S. SAJWAN

2

1(Department of Disaster Management, Disaster Mitigation and Management Centre, Dehradun,

Uttarakhand, India. 4 Subhash Road, Uttarakhand Secretariat, Dehradun- 248001) 2(Department of Disaster Management, Uttarakhand State Disaster Management Authority,

Dehradun, Uttarakhand, India. 4 Subhash Road, Uttarakhand Secretariat, Dehradun- 248001)

INTRODUCTION Located in Himalayan region the state of Uttarakhand is vulnerable to a number of natural hazards

that include earthquake, landslide, flood, flash flood, avalanche and drought. Other disasters, heavy

localised precipitation and associated flash floods are among the most devastating disasters in the Himalayan mountainous belt. Sudden increasing runoffs through the streams during monsoon season

create flash floods situation which affect habitations and infrastructure downstream.

In the last decade, it is frequently occurred in the Himalayan state of Uttarakhand that caused heavy loss of human life, property and infrastructure. Some major extreme events in the same durations are:

(i) August, 2009 Lah- Jhekla tragedy in Pithoragarh [1]; (ii) In the year 2012 particularly heavy

rainfall was received between 4 and 6 August, 2012 in Asiganga valley in Uttarkashi and 13 and 16 September at Okhimath in Rudraprayag [2, 3]; (iii) Heavy rains and associated deluge on 16/17 June

2013 in the catchments of the Mandakini valley in Rudraprayag [4]; (iv) On July, 2016 debris flow

occurred after heavy rainfall in Didihat, Bastari and Naulra in Pithoragarh [5]; (v) Localised heavy

rains in the early hours of 14 August, 2017 in the catchment of the tributaries of Kali river, particularly Simkhola Gad and Malpa Gad [6]. These hydrometerological disasters claimed many

human lives, property, infrastructure and livelihoods. These are often attributed to climate change.

Additionally, unscientific habitation pattern in close vicinity of local streams, over transported sediments/fan deposits and colluvium has often resulted in devastation in the area. The area also falls

in Zones IV and V of Seismic Zonation Map of India [7] and had suffered an earthquake on 1991 [8].

Despite industrialisation, growth, development and urbanisation overwhelmingly large proportion of

the population of India (68.8 percent) resides in rural areas and with 28.4 percent of the population

ABSTRACT Hydro meteorological disasters on 18

th August, 2019 in the catchment of Khaneda Gad, a

tributary of Pabbar River caused devastation in Mori tehsil of Uttarkashi district. Heavy and concentrated rainfall in the upper reaches of the catchment of Khaneda Gad resulted in flash

floods and debris flows in the downstream areas. These incidences killed 18 people while 3

went missing and 74 animals were lost. Besides, these inflicted heavy loss of property,

infrastructure and livelihoods at various villages. The losses in the event were aggravated due to high relief of the area and unscientific habitation pattern in close vicinity of the

streams. Apple crop cultivation is the main livelihood option for the inhabitant of the area.

This also badly affected in these incidences. The purpose of this paper is to highlights the causes of disasters and its effects on inhabitants of affected areas. As also suggestions for

future disaster risk reduction and sustainable development within the above said region.

KEYWORDS: Heavy localised precipitation, flash floods, causes, damages, sustainable

development, Uttarkashi

FLASH FLOODS IN HIMALAYA WITH SPECIAL REFERENCE TO MORI TEHSIL OF....

Copyright ⓒ 2016 IJCRM | Page 11 |

and 71.4 percent of the workforce engaged in agricultural sector livelihood of large proportion of the

people is still dependent on agriculture [9].

Situation is no different in the provinces and despite growth of secondary and tertiary sectors after the

formation of Himalayan province of Uttarakhand in India in the year 2000, agriculture is major

economic activity for overwhelmingly large population. 70,36,954 of the 1,00,86,292 persons of the province (69.8 percent) reside in rural areas and with 15,80,423 persons being cultivators and

4,03,301 engaged as agricultural labourers 19.7 percent of the population or 50.8 percent of the

workforce of the province is engaged in agriculture sector [9].

Heavy localized precipitation and associated floods of 18 August, 2019 in Mori tehsil of Uttarkashi

district that caused loss of 21 human lives and 74 animals lost. Besides floods, local and concentration

rainfall in the area induced slope instability and triggered mass movement in the area. The water laden down slope moving mass was observed to have overrun the houses and cultivated lands at various

places. 2 motor bridges on Arakot-Chiva-Balcha and Tikochi-Kunal-Duchanu roads are damaged

along with 2 pedestrian bridges on Arakot-Chiwan track and near Dikochi damaged. Around 10 roads were disrupted in the affected area. Households of 2,021 of 15 villages was affected in these

incidences. These include Chiwan, Gokul, Jhotadi, Balawat, Moldi, Arakot, Jagta, Dhara, Dagali,

Duchanu, Monda, Tikochi, Kalich, Makuri and Barnali villages are adversely affected. Details of the same is given in Table 1.

Table 1. Details of the households of 2,021 of 15 villages in Mori Tehsil of Uttarakashi district

Sl. No. Affected villages Households

1 Chiwan 262

2 Dagali 120

3 Jhotadi 168

4 Dhara 120

5 Duchanu 119

6 Gokul 182

7 Kiranu/moldi 147

8 Monda 108

9 Makuri 104

10 Arakot 186

11 Kalich 106

12 Balawat 164

13 Barnali 35

14 Jagta 140

15 Tikochi 60

Total 2,021

Apart from the loss of human lives, the affected population often suffers loss of their agricultural lands. The main land use practice in the study area is terrace farming and cultivation of apple crop. A

large amount of apples have been exported from the area. Apple crop cultivation is the main

livelihood option for the local people which was also badly affected in these incidences. This

adversely affects the economy and quality of life of the affected population. The main objective of this present study is to assess the causes and consequences of the disasters and suggestions for future

safe developmental planning in the area. This study is based on field work undertaken in the area

aftermath of the disaster.



CHANGE IN RAINFALL AND CLIMATE Change in rainfall pattern has been experienced during previous some years. Though according to Indian Meteorological Department (IMD) data there is not much change recorded in the average

rainfall in Uttarakhand but change in rainfall intensity and duration cannot be ruled out. Description

of average monthly rainfall (mm) in 15th June to 20

th August 2019 in Uttarakhand is given in Table 2.

Table 2. District wise average monthly rainfall (in mm) from 15th

June to 20th August 2019 in

Uttarakhand.

2019 June July

August

(upto20th

)

Average Rainfall

(01 Jun to 20 Aug)

District ACK NOR ACK NOR ACK NOR ACK NOR

Almora 77 152.3 179.4 273.3 190.9 189.9 149.1 205.2

Bageshwar 84 152.3 246.2 273.3 427.7 189.9 252.6 205.2

Chamoli 50.3 100.5 209.1 268.4 338.2 203.2 199.2 190.7

Champawat 98.4 213.7 267.5 473.2 346.7 266.6 237.5 317.8

Dehradun 89.8 180.8 336.3 554.8 286 385.4 237.4 373.7

Pauri Garhwal 23.1 161.1 202.6 419.8 267.9 312.9 164.5 297.9

Tehri 67.2 135.6 192.3 344.9 220 255.3 159.8 245.3

Haridwar 21.1 118.2 262.9 331.6 233.8 253.1 172.6 234.3

Nainital 134.4 230.7 498 491.9 271.9 291.5 301.4 338.0

Pithoragarh 133.7 258.6 423 539.5 356.6 338.3 304.4 378.8

Rudraprayag 101.8 208.1 351.2 521.5 448.6 389.8 300.5 373.1

Udham Singh Nagar 136 150.5 328.3 378.5 216.1 222.9 226.8 250.6

Uttarkashi 84.6 206.7 243.2 415.6 248.6 273.5 192.1 298.6

Average 84.7 174.5 287.7 406.6 296.4 274.8 222.9 285.3

ACK – Actual, NOR – Normal

Although the rainfall recorded is much less but due to absence of localized precipitation data of extreme event, it is not clear that how much rainfall took place in the area around Arakot while the

area faced large scale devastation. It has been observed that the frequency and recurrence of heavy

localized precipitation events has increased over the period of time.

MATERIALS AND METHODS The disastrous region is located in the mountainous terrain and enjoys good road connectivity and can be approached from Dehradun by Vikasnagar – Chakrauta – Tiuni motor roads and falls in Survey of

India toposheet number 53 E/16. Tiuni town is situated at a distance of 158 kilometers from Dehradun

via National Highway (NH -707). Arakot is situated on the banks of the Pabbar River and at a

distance of around 24 kilometers upstream to Tiuni town. The most devastated area can be approached by the link road bifurcating from the Arakot along the Khaneda Gad catchment. Survey of

India toposheet number 53E/16 on the scale of 1:50,000 have been used to prepare the location map

of the area (Figure 1).



Figure 1: Location map of the devastated area

GEOLOGY AND GEOMORPHOLOGY Geologically, the area is occupied by rocks belonging to Kulu Group and undifferentiated Jaunsar

Group. The Kulu Group of rocks exposed in the area and Thrusted by Kulu Thrust over the Jaunsar

Group. The Kulu Group is made up dominantly of streaky and bended gneiss, and schist and quartzite. The foliation planes were observed to dip towards NW at angles 50º. The undifferentiated Jaunsar

Group is the youngest rock Group in the area exposed along Pabber valley. It comprises greywacke,

shale, phyllite, quartzite and dolomite. The bedding planes were observed to dip towards E-SE at angles 45º.



Geomorphologically, the area is drained by ENE-WSW and S-SSE flowing Pabbar River which is an

important tributary of Tons river. It is fed by Khaneda Gad in the Uttarakhand which is meeting in the area around Arakot. It is 5

th order stream originating from an approximate elevation of 3912 m above

mean sea level. Mostly the drainage system of the area is of dendritic type. The Khaneda valley

exhibits characteristically distinct rugged mountainous topography of the both Lesser and Higher

Himalayan terrains. The imprints of geological structures and lithology are observed in the area in the form of strike ridges and deeply incised valleys. The area is observed to be dissected by several ridges

and the ground elevations vary from about 1150 to 3230 meters above mean sea level. In the Khaneda

valley most motor roads were disrupted by landslides and flash floods and the area was largely approached on foot. During field investigations accumulation of huge amount of boulders and debris

at Tikochi and bank erosion by Khaneda Gad at Mauldi was observed.

ON 18TH

AUGUST, 2019 DISASTROUS MORI TEHSIL According to eyewitness accounts cloudburst incidence took place around Arakot along with Khaneda

Gad valley after heavy rainfall in the morning hours (around 0445 hr) in which Arakot, Mauldi, Makuri, Tikochi-Nagwara, Snail, Duchanu etc. villages were severely affected and devastated. Heavy

rainfall/Cloudburst like incidences took place in two phases, in first phase at 4.45 AM on 18th August,

2019 Khaneda Gad valley devastated by heavy downpour and associated flash floods afterwards in

second phase on the same day at 6.00 AM extreme weather events occurred at Arakot and Snail area. Unprecedented damage and destruction occurred in the Khaneda Gad valley. It has been observed

during field investigation that Khaneda Gad a tributary of Pabbar River has changed its course and

shifted at several locations, due to heavy discharge. These caused loss of human life, property and

infrastructure in the area. High sediments leaden discharge through steep gradient streams in the area around Arakot washed away road which lead to Himachal Pradesh and damaged many structures

which was exist its flanks (Figure 2a).

Continuous localised precipitation in the catchment of Khaneda valley caused spate in its course that

has considerably changed the original topography of the area. Major destruction and damages have

been occurred in Tikochi village (Figures 2b and 2c). Besides, Chiwan, Gokul, Jhotadi, Balawat,

Moldi, Jagta, Dhara, Dagali, Duchanu, Monda, Kalich, Makuri and Barnali villages are adversely affected. The landslides and toe erosion by the streams caused breaching of the road and overran the

vehicles in the area (Figures 2d and 2e).

Human losses in disaster induced by heavy rainfall on 18

th August 2019 in Mori Tehsil are (i) 1

missing and 6 dead in Arakot village; (ii) 1 missing and 5 dead in Makuri village; (iii) 1 missing and 3

dead in Snail village; (iv) 1 dead at Nagwara near Tikochi village; and (v) 1 missing and 3 dead in Sanol village.

One helicopter of Heritage Aviation crashed in the affected area while engaged in relief and rescue

operations (Figure 2f). 3 persons onboard the ill fated chopper including Pilot and Co-Pilot died in the incidence. Detail of the losses is given in Table 3.



Table 3. Losses incurred in the disaster of 18th

August, 2019 (Data source: State Emergency

Operations Centre)

Sl.

No.

Causes of losses Human loss Animal loss

Dead Missing Injured Dead Missing

1 Heavy rainfall and cloudburst 15 3 12 74 3

2 Helicopter crashed during

search & rescue operations

3 0 0 0 0

3 Emergency lending due to Helicopter breakdown on

hours of search & rescue

operations

0 0 2 0 0

Total 18 3 14 74 3

Despite road blockade on all sides teams of Police, State disaster response force (SDRF), Disaster

Mitigation and Management Centre (DMMC), Health, and administration have managed to reach the affect area and have established the base at Arakot. The relief camp was established in the same area

for the affected people. Total of 410 affected people were sheltered in these. Out of total, 174 people

sheltered in Forest Guest House and 201 people sheltered in Primary School while remaining 35

people sheltered in Government Intermediate College.

a b

d c



Figure 2: On 18

th August, 2019 hydro-meteorological disaster induced losses; (a) high velocity

discharge through local streams damaged road and other structures in Arakot; (b) damaged shops due

to debris flows in Tikochi village; (c) damage to bridge and washed away Allopathic Hospital due to flash floods at Tikochi village; (d) road leading to Arakot-Chiwan blocked due to landslide; (e)

vehicles washed away due to breaching of road and debris flows; (f) crashed helicopter of Heritage

Aviation in the affected area

CAUSES OF DEVASTATION IN THE AREA Heavy localised precipitation/ cloudburst like incidences took places in Mori tehsil resulted heavy discharge in streams causes toe erosion, landslide, debris flow incidences at a number of places.

Habitations located along the close vicinity of the river and tributaries are severely damaged while

settlements vulnerable for the landslide due to slope made up of overburden / loose materials as well as old landslide mass have been badly affected and damaged. These inflicted heavy loss of human

lives, property, infrastructure and livelihoods.

Mostly tributaries and seasonal streams have been observed to be overwhelmed by debris flows and heavy discharge of water during these incidences and flash floods occur in downstream areas, as was

noticed in Arakot, Snail, Nagwara and Tikochi areas. Some major causative factors for the mass

instability are as follows:

Heavy localised precipitation in a short period of time and change in climate

High dissected hills and steep valley slopes

Agricultural practices over fan deposits, old landslide mass and colluvium

Fragile and weak rocks due to major Thrust/Fault

High relief which promoted fast and high surface runoff

Unscientific habitation pattern in close vicinity of the local streams, over transported

materials/fan deposits

The area falls in physiographic region between 1200 to 3500 meters altitude zone

Overburden slopes undercut by both seasonal streams and perennial streams

Excessive rainfall increases pore water pressure that resulted mass wastage, landslides and

debris flows

RESULTS AND DISCUSSION Heavy downpour and associated flash floods is not an uncommon in Uttarakhand Himalaya and it has

become quite frequent in last decade due to change in weather regime. This is attributed to change in climate. A disaster struck on 18

th August, 2019 in the area around Arakot after localised heavy

precipitation in Mori tehsil of Uttarkashi district. This heavy precipitation resulted into the swelling of

Khaneda Gad, a tributary of Pabbar River. The water filled up streams that overflowed, particularly

f e



during the early morning on 18th August, 2019, killing about 18 persons while 3 went missing and 74

animals were lost. Thus, the furious Khaneda Gad and local streams destroyed the property, infrastructure and cultivation lands that came in its way. The landslides and toe erosion by the streams

caused breaching of the roads in the area around Arakot and catchment of Khaneda valley region at

various places and bridges of Arakot-Chiwan-Balcha and Tikochi-Kunal-Duchanu roads were

damaged.

The present study area is occupied by rocks of Lesser Himalaya and Higher Himalaya. It mainly

consists of gneiss, schist and quartzite. Geologically, the rocks in this area are found highly deformed, degraded and dissected by structural discontinuities. Geo-tectonically, the area is traversed by several

faults and thrusts, which are considered to be geodynamically active.

Geomorphology of the area indicates that the surface slopes consist mostly of fluvial and colluvium which are mostly unconsolidated and loose in nature. Due to morphological setting of the devastated

areas, the streams have high sinuosity and hence, high level of erosive capacity, especially when these

are loaded with sediments. Thus, the terrain conditions combined with weather conditions and unscientific habitation pattern made a favorable environment for such a disastrous process to take

place in the same region.

Unscientific habitation pattern in close vicinity of the streams are therefore required to be identified

and marked safe or unsafe by respected agency and accordingly all anthropogenic interventions in

these areas have to be banned. In case people are already residing in such areas provision has to be

made for their timely relocation. This provision in the long run would encourage people to settle down at safer places due to enhanced awareness in this regard.

CONCLUSIONS Located in the adverse physiographic region and socio-economic conditions, Mori tehsil of Uttarkashi

district is vulnerable to heavy localised precipitation and associated flash floods. On 18th August,

2019 heavy localised precipitation cause devastating flash floods in the catchment of Khaneda Gad in Mori tehsil. As many as 18 persons were died while 3 persons went missing and 74 animals were lost

in these incidences. Apart from the loss of human lives, the affected population often suffers loss of

their dwellings, animal stock, cultivation lands and business. This adversely affects the economy and quality of life of the affected population.

The area also fall in Zones IV and V of Seismic Zonation Map of India and had suffered an

earthquake on 1991 which caused weakening of rock masses, landslides and damaged human settlements. High relief, fragile mountainous slope, overburden, heavy localised precipitation and

change in climate are the responsible and controlling factors for the extreme weather events and

associated flash floods in the area. Besides, unscientific habitation pattern in close proximity of streams, over transported sediments, colluvium are deduced to be the main causes of the devastation

in the area. Recent anthropogenic activities like road cutting, extension of apple orchards instead of

trees having deep roots and infrastructure development concentrated along valley side further aggravated the situation.

Although, the hydro-meteorological events cannot be restricted but loss of life and property can be

reduced by taking certain precautionary measures. In such areas constructions should be carried out after through and detailed geological and geomorphological studies. The identified areas as a high risk

require more detailed mapping.

In view of vulnerability to such hydro-meteorological events, network of weather observatory and

early warning system must be installed widely in the same region. Meteorological parameters like the



wind velocity, volume of rainfall, percentage of relative humidity, flood levels etc. should be

monitored regularly [10]. They are providing timely alerts to the community in any emergency situation. According to timely warning dissemination, inhabitants of the area will be shifted to safer

places and we can be safe the invaluable life.

Acknowledgements The Executive Director, Disaster Mitigation and Management Centre, Department of Disaster

Management, Uttarakhand Secretariat, Dehradun, India is acknowledged for their suggestion,

cooperation and valuable support. Colleagues at Disaster Mitigation and Management Centre and Uttarakhand Disaster Management Authority are thanked for cooperation and support.

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